Expansion valve



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EXPANSION VALVE Filed June 22, 1953 .2 5 MM 6 q M 1 WWW H M 2 z d fl M f.v a 7 W.

6 Q mm M M l 6 w a a m a 0 k 9 4 a 4 2 A z z w i w w iww Patented Oct.5, 1937 "UNITED STATES,

PATENT OFFICE Claims.

able of being easily assembled in accurate relation to each other; toprovide a valve which permits accurate and positive seating of the valveelement; to provide an expansion valve embodying but a. single spring;to provide a valve struc ture having a floating valve or novelconstruction; to provide a valve structure having a full floating valvepositively operated in both directions of movement; to provide anexpansion valve in'which a full floating valve is connected to thepressure operated member thereof for positive inter-related movement; toprovide a'valve of the type described having a full floating valveelement positively movable vertically in opposite directions; andtoprovide an expansion valve having novel means for positively placing itin open position.

Other objects include the provision of a novel form of needle valve andconnection with its operating' member, insuring perfect sealing of thevalve at all times.

Further objects include the provision of a novel means for operating anexpansion valve; the provision of a novel thermostatically controlledexpansion valve; the provision of a novel connection between athermostatically operated element and an expansion valve whereby theabsorption of heat in the expansion valve will not affect the operationof .the thermostatic device; and the provision of'a thermostaticallyoperated expansion valve having a novel form of connection between thethermostatic element and the valve proper permitting ease and accuracyof adjustmerit thereof. g

The above being among the objects of the present invention, the sameconsists in certain novel features of construction and combination ofparts to be hereinafter described with reference to the accompanyingdrawing, and then claimed, having the above and other objects in view.

In the accompanying drawing which illustrates suitable embodiments. ofthe present invention and in which like numerals refer to like partsthroughout the several different views,

(01. sir-2s) Fig. 1 is a vertical sectional view taken centrally throughan expansion valve.

Fig. 2 is a vertical sectional view taken on the line 22 of Fig. 1.

Fig. 3 is -a fragmentary horizontal sectional 5 view taken on the line33 of Fig. 1.

Fig. 4' is a horizontal sectional view taken on the line 4-4 of Fig. 1.I

Fig. 5 is a fragmentary, partially sectioned, partially broken, enlargedview showing with 10 greater clearness the construction of theconnection between the valve proper and the member to which it isdirectly connected in the expansio valve shown in the previous. figures.4

Fig. 6 is a view similar to Fig. 1 but showing 15.

the construction therein modified for operation by a thermostaticelement.

As is well understood in the art, expansion valves are used inconnection with refrigerating apparatus for controlling the flow ofliquid re- 20 frigerant from the high pressure sideof the system to thelow pressure side of the system. Such valves are controlled in a varietyof different ways such, for instance, as by the pressure in the low sideof the system, the temperature of the evaporator ,or the space which theevaporator cools, and in many cases by a float. One of the principalfeatures of the present invention is in the construction of a valveitself which is applicable for use in connection with any of the abovetypes of expansion valves or apparatus but, for the purpose ofillustration only, the invention is herein illustrated in connectionwith an expansion valve of the pressure operated type and one of thethermostatically operated type, the application of the. valve itself tothese structures involving further novel features constitutingadditional features of the present invention.

It is also well understood in the art that in connection with suchvalves, except for the float 40 control type, it is necessarygto have amovable wall of some suitable type to serve either as a pressureresponsive element, or as a seal, or both, and while in the broaderaspects of the present invention such movable wall may take the form ofa bellows, a diaphragm or a piston, the former is shown as beingpreferred by way of illustra tion, although in some of the narrowerphases of the present invention as will hereinafter be specificallypointed out and claimed, the bellows forms a part of a new and novelcombination. Referring now to the drawing and particularly to Figs. 1 to5 inclusive, an expansion valve is shown 'as including a casing I0through which refrigerant is adapted'to flow as controlled'by themechanism enclosed therein. The liquid refrigerant is adapted -to beintroduced into the casing, as best illustrated in Fig. 4, through aconnection member l2 threaded into a passage l4 formed in the casingIII, a screen l6 of cylindrical formation and having a closed end (notshown) being suitably associated with the connection member l2 andprojecting within the passage in spaced relation to the walls thereof soas to filter the refrigerant flowing to the valve and remove foreignmaterial therefrom. The passage I4 is connected by a cross passage l8with the lower end of a vertically extending passage alignment with thepassage 20 is provided with close but normally spaced relation withrespect a a threaded opening 26 normally closed by the plug 28 andthrough which opening the plug 22 and other parts of the valve structuremay be inserted or removed. The plug 28 is provided with a recess 30centrally disposed in its lower face, the purpose of which will be laterdisclosed.

The right hand end of the casing l is originally formed fully open andthis open end is closed .by a bellows 32 having a head 34, and an open,

end which is sealed to a ring 36, the periphery of the ring beingreceived against a shoulder 38 formed at the open end of the casing I0and to which the ring 36 is suitably sealed as by solder. A cap 481sscrewed onto the open end of the casing l0 over the openend of thebellows 32 and is provided with a central boss 42 axially aligned withthe bellows 32. This boss is provided with a central axial opening inwhich is threadably received a headed bolt 44, the head of whichprojects into the bellows 32 and into relatively to the head 34 thereof.A cup member 46 is positioned within the bellows 32 and its bottom issoldered or otherwise fixed to the head 34. The open end of the cup 46which extends to a point adjacent the open end of the bellows 32 isinwardly turned at its open end to form an annular flange 48 withinwhich is removably received a split ring or washer 58 which serves as aseat for a conical coil spring 52 constantly maintained undercompression between the ring 58 and the head of the bolt 44. Bythreading the screw inwardly or outwardly in the b05512 it will beapparent that the tension of the spring 52 acting to.collapse thebellows 32 may be varied, and consequently the amount of suction withinthe casing ll] necessary to expand the bellows 32 a given amount may becorrespondingly varied. ,Preferably the exterior surfaceof the boss isthreaded and receives thereon a smaller cap member 54 which maybe sealedto the cap 4|] through the employment of a suitable gasketsuch as 56.

Pivotally mounted within the casing between twp cone pointed pins 58threaded through opposite walls of the casing l 8 is a bell crank 60 onearm 62 of which extends to the left as viewed in the drawing in agenerally horizontal direction and the other arm 64 of which extends ina generally downwardly direction and is provided with a partiallycylindrically formed end 66. The lengths of the arms 62 and 84 may, ofcourse, be varied in their respective lengths as necessity or desiresdictate. The end 66 is relatively closely received in a verticallyextending rectangular opening provided in a bracket 18 which is solderedor otherwise suitably secured to the outer surface of the head 34 of thebellows 32, this connection being such as to permit rectilinear movementof the end of the bellows 32 and the bracket 10. while causingcorresponding positive pivotal movement of the bell crank 68 in eitherdirection.

The free end of the arm 62 of the bell crank 60 is provided with arelatively large vertically disposed opening 12 in axial alignment withthe aperture in the plug 22 when the arm 62 is in horizontal positionand threadably received in the opening 12 is a collar or ring member 14.Now referring to Fig. 5 in which this portion of the apparatus is shownin greater detail, it will be'noted that the collar I4 is provided witha bore 16 which is of smallest diameter at a point approximately midwayits length and flares outwardly in both directions therefrom. The collar14 is also provided with a transverse opening 18 at its. point ofminimum internal diameter in which is received a pin 80. A valve orvalve element 82 of the needle type is relatively closely received inthe bore 16 at its point of minimum diameter and depends verticallytherefrom, its pointed end 84 being received within the aperture 23' ofthe plug 22 and cooperating therewith to control the flow of fluidthrough the plug 22 into the casing I0. At the point where the valveelement 82 projects through the collar 14 it is provided with a,transverse opening 86 in which the pin 88 is relatively closelyreceived. The opening 86, in a manner similar to the bore 16, is ofminimum diameter adjacent the midpoint of its length and flaresoutwardly in either diree tion therefrom, the walls of the opening 86 atthe point of minimum diameter thereof relatively closely receiving-thepin 80. As will be apparent,

with this construction the valve element 82 is so supported relative tothe arm 62 of the bell crank 60 that the poirt 84 of the valve elementis allowed a limited amount of free floating movement in all directionsexcept axially and consequently the point 84 is always capable of freelymoving so as to properly accommodate itself to its seat in the plug 22.

'As will be noted, the upper end of the valve element 82 projectsupwardly beyond .the upper end of the collar 14 and is provided ampleclearance for its movement in the opening 30 in the plug 28. The upperface of the collar 14-, which is of greater diameter than the opening30, is positioned in normally adjacent but spaced relation with respectto the lower face of the plug 28, and the spacing between these parts issuch as to permit contact of the collar 14 with the cap .28 for.thepurpose of limiting excessive expansive movement of the bellows 32should the occasion arise, and thus prevent possible rupture of thebellows from such cause. Likewise, engagement of the valve element 82with the plug 22 limits movement of the bellows in the oppositedirection.

The construction of the valve element 82 and its supporting mechanism isof particular importance for the reason that when properlyvconstructedand assembled it provides a positively operated valve that is alway'spositive in its seating and free of any sticking tendency. This is ofutmost importance in connection with refrigerating mechanism as the lackof'a proper seat for the valve element in expansion valves is one ofpassage and these openings may then be tapped. the plug 22 inserted inplace, and then the bellcrank 60 may be introduced through the opening26 and the pins 58 threaded through the casing and'into a position toengage the bell crank 60.

A suitable locating tool (not shown) may now be threaded through theopening 12 in the arm 52 of the bell crank 60 and located'in theaperture 23 of the plug 22. The pins 58 may then be threaded either inand out until it is apparent that the locating tool is properly locatedin the aperture 23 and the pins 58 exert the proper pressure in theirbearings in the bell crank 60 without interfering with the proper freepivotal movement thereof. Solder, such as 88, may then be applied to thecasing I8 over the ends of the pins 58 to seal the casing from possibleleakage at this point and to lock the pins in adjusted position.threaded inwardly until its head contacts the head 34 of the bellows 32thus positioning the bell crank 60 in a definite location. The locatingtool 3 may now be removed from the opening 12 and a suitable bushing maynow be inserted in the opening 12 and employed for guiding a suitabletool for forming a shallow seat for the valve element 82 at the uppermargin of the aperture 23 in the plug 22, and aftersuch tool and bushingis removed the collar 14 may be slipped over the valve element 82, thepin88 inserted in place and this assemblage threaded into the opening 12in the arm 62 to its final position.

After this mechanism has been located in the manner described and thescrew 44 backed off, it will be apparent that, because of the freedom ofthe universal movement of the valve. element 82 in the arm 62 of thebell crank, and particularly in view of the fact that the valve elementis pendant, or positioned with its axis vertically and hanging from thepin 88, the coned end 84 of the valve element 82 will always find itsproper seat upon closing movement of the valve. This is particularlytrue in view of the fact that the bell crank 60 will always be in thesame position when the valve is moved to closed position and further dueto the fact that the valve element 82 will seldom be lifted from itsseat a distance greater than .010 of an inch during operation'ofthevalve.

The operation of the above described valve will of course be apparent tothose skilled in the art and briefly may be stated as follows: When thepressure on the low side of the system drops below a predeterminedpoint, which may be variably controlled by manipulation of the screw 44as previously described, the length of thebellows 32 will be increased,the head 34 of the bellows moving to the left as viewedin the drawing.Movement of the head 34 will cause an equal and positive movement of thebracket Illv which in turn will cause an equal and positive movement ofthe end 66, of the bell crank 60, causing the bell crank to pivot aboutits pivotal axis in a clockwise direction as viewed in the figures.'lhts movement of At this point the screw 44 may be the bell crank willpositively cause the free end of the arm 62 thereof to move upwardly andin moving upwardly will positively lift the valve element 82 and retractthe end 84 thereof partially from the aperture 23 in the plug 22 andwill 5 thus permit liquid refrigerant to flow into the casing throughthe aperture 23 and out of the casing through the passage 24 into thelow pressure side of the system. As soon as the pressure'in the lowpressure side of the system increases sufficiently to permit the spring52 to contract the bellows 32 to such an extent as to move the valveelement 82 again to closed position, the flow of liquid refrigerant intoand out of the casing I 0' will be discontinued. Furthermore, rise inpressure on the low side of the system including the interior of thecasing 10, will act on the bellows 32 to additionally force the valvepoint 84 against its seat. It is to be noted that during openingmovement of the valve, the valve element 82 is positively moved towardopened position and,.likewise, during closing movement of the valve thevalve element 82 is positively moved toward closed position and the end84 of the valve element is always capable of floating so as to insureits finding is correct and 25 perfect seat in the plug 22. In thisrespect it will also be understood that because of the positive supportfor the bell crank 60 which insures the end 62 following the same pathof movement at all times, the pressure of the spring 52 can have noeffect whatsoever on tending to divert the end 84 of the valve away fromproper seating position. It is also noted that the structure involvesaminimum number of operating parts which may be assembled into arelatively small structure which makes for ease and economy inproduction. Also, that because of the construction and arrangement ofthe parts, any particles of grit or other foreign matter that may findits way into the casing will not aifect the proper movement of the partsor interfere with the proper working -of the mechanism. It-may also benoted "that shouldit be desired for any reason or other tot positivelyhold the valvein open position the cap 54 may be removed and the screw44 threaded in- 45 wardly until its head contacts with the bottom of thecup 46 and moves the valve to open position. I

This feature not only serves as an aid in the proper assembly of thedevice, but also provides means whereby positive opening movement of thevalve 50 may be accomplished should the occasion arise. By threading thescrew 44 in the opposite direction to increase .the compression of thespring 52, it enables the usual cooling unit or evaporator of arefrigerating system to be removed without danger of loss of refrigerantthrough the expansion valve.

In Fig. 6 is illustrated the application .of substantially the samemechanism illustrated in the previous figures to an expansion valve ofthe thermostatically operated type. As will be noted in this figure, theparts at the left hand end thereof are identical to the parts previouslydescribed except that a cap 90 of different design is substituted forthe cap 40 shown in Fig. 1, the metal (55 cup 46a within the bellows 32has been modified to provide an inwardly facing cone-like projection 92centrally of its bottom and the spring 52 has been replaced by a spring94 f slightly different shape and size. The cap 9|] in this case threadsonto the casing ill in substantially the same manner as that-previouslydescribed but is provided with a threaded portion 96 on which isthreadably received what may be known as an insulating spacing casing88, preferably formed from suitable non-metallic heat insulatingmaterial as, for instance, rubber or some phenolic condensation productsuch as that marketed under the name of Bakelite.

The casing 98 is provided with a head I having a central axiallyprojecting boss I02 in which is closely but slidably received'the righthand end of a tube I04. The tube I04 is preferably formed of the samematerial as the casing 98. The cap 90 is provided with a centrallyapertured boss I06 which is internally threaded for cooperativeengagement with the corresponding threaded portion of the tube I04 whichprojects therethrough. The right hand end of the boss I06 as viewed inthe figure may be inwardly tapered on its end face and the exterior ofthe boss threaded and provided with a nut I08" which may cooperatetherewith to compress packing such as 0 about the tube I04 so as to'ffect a gland therefor. The left hand end of the tube I04 projects intothe cup 4011 in the bellows 32 and at its extremity isprovided with aperipheral flange I I2 between which and the ring Eli-the coil spring 94is maintained under compression.

Midway .of its length the casing 88 is preferably provided with anaperture such as H4 and the tube I04 in approximate alignmenttransversely with the opening H4 is preferably provided with anhexagonal surface II6 enabling a wrench to be inserted into the casing98 through the aperure H4 and into engagement with the tube I04 topermit rotation thereof and thus vary the stress of the spring 94 forthe purpose of modifying the pressure required to actuate the bellows 32and consequently the valve element 82'.

Threaded onto the right hand end of the casing 98 is another casing I26having an end wall I22. Within the casing I20 is a bellows I24, the headof which is fixed against movement to the end wall I22. The left handend of the bellows I 24 is provided with a head member I26 the centralportion of which is depressed inwardly-relative to the bellows to form acup I28 and the bottom of the cup is formed to provide an inwardlyextending cone-like projection I30 similar and opposed to the projection92 previously described. Freely siidably received within the tube I04and extendof the bellows I24 communicates through a tube I34, which isusually of the capillary type, with .the usual control bulb or feelerleg I36, it being understood that the bulb I 36, tube I34 and bellowsI24 is filled, partially orotherwise, with a suitable refrigerantadapted to vaporize at a desired given temperature, and that the bulbI36 is positioned in,'against or in proximity to the object or chamber,the temperature of which it is desired to control. Obviously, when thetemperature of such chamber increases sufficiently to cause a portion ofthe refrigerant in the bulb I36 to vaporize, the increased pressure inthe bulb I36 caused by such vaporization is transmitted through the tubeI34 to the bellows I24 and tends to expand the bellows I24. Uponexpansion of the bellows I24 the rod I32 will be moved to the left, asviewed in the figure, and cause a like movement of the head of thebellows 32 which, as previously described, will cause the valve element82 'to be lifted from its seat and permit liquid refrigerant to flowinto the casing it. When this flow of' refrigerant through the casing itand into the low pressure side of the refrigerating system causes apredetermined drop in the temperature of the part controlled by the bulbI36, the refrigerant in the bulb I36 will be condensed, causing'a dropin pressure in the tube I36 and bellows I24 which will permit the spring34 to contract the bellows 32 and move the valve element 82 to closedposition.

It is to be particularly noted that in connection with thermostaticallyoperated expansion valves of the general type indicated, considerabledifflculty has been experienced in previously suggested constructionsdue to the fact that the connection provided between the member moveddirectly by the tube I36, the bellows I24 in the present case, has hadsome form of metallic connection with the casing of the expansion valveproper and, due to the fact that the liquid refrigerant flowing throughthe expansion valve reduces the temperature thereof to a materialdegree, heat is absorbed from the wall moved by the tube I36 and causesthe gasified refrigerant therein to be liquefied, thus either destroyingor at least rendering inaccurate or unsatisfactory the accurate resultsfor which the device is intended. With the present construction by theemployment of the heat insulating casing-98, tube I04 and rod I32 thepossibility of heat absorption from the bellows I24 and liquid containedtherein by the expansion valve proper is entirely eliminated so that anycapable of various modifications and changes without materiallyaffecting the invention involved and, accordingly, it will be apparentthat formal changes may be made in the specific embodiment of theinventiondescribed without departing from the spirit or substance of thebroad invention, the scope of which is commensurate with the appendedclaims.

I claim: i 1. In a valve structure, in combination, a casing having avalve seat, a member in said casing movable along a fixed path andhaving an opening therein, said opening having .a wall portion ofrestricted dimensions and the walls thereof flaring outwardly from saidportion, a needle valve passing through said opening and relativelyclosely received by said restricted wall portion, said needle valvehaving a transverse opening therethrough, a central portionof the lastmentioned opening being of restricted diameter, and a. pin extendingthrough said opening in said pin and fixed against movement relative tosaid member at the point of wall restriction of said opening therein,the point of said valve lying in cooperative relation with respect tosaid seat.

2. In a valve structure, in combination, a casing having a valve seatprovided therein, a bell crank pivotally supported in said casing, anarm ofv said bell crank having a threaded opening therein, an aperturedplug threadably received in said opening, the aperture in said plugbeing of restricted diameter between its endsand flaring outwardlytherefrom, a needle valve projecting through said aperture with itspoint in 00- operative relation with respect to said seat, said needlevalve having a transverse opening therethrough at the point ofrestriction of said apering outwardly therefrom, said plug also havingavtherein, a bellows sealed) to said casing and ture in said plug, saidtransverse opening being of restricted diameter between its endsandflartransverse opening therethrough at the point'of restriction of theaperture therein, and a pin extending through said transverse apertures.

3. In awalve structure, in'combination, a casing having a valve seattherein and an opening closing said opening, a spring seat secured tothe movable end of said bellows, a headed screw projecting into saidbellows and beyond said seat,

a spring held under compression between said seat and the head of saidscrew,a bell crank supported for pivotal movement within said casing,

means connecting one arm of said bell crankto said movable end of saidbellows, said connection being so constructed and arranged that said abell crank has positive equal movement with said bellows in bothdirections of movement of said bellows, a needle valve cooperating withsaid valve seat, and a connection betweensaid needle valve and theremaining arm of said bell crank, the last mentioned connection being soconstructed and arranged asto cause constantly positive equal movementof said needle valve in both directions "with Said remaining arim-saidscrew being movable to a position to engage the said bellows and move itto a position to positively unseat said valve.

4. In a valve structure, in combination, a caspivotally mounted withinsaid casing, a slidable connection between one arm of said bell crankand the closed end of said bellows, said connecs tion being soconstructed and arranged as to cause positive equal movementof the endof said arm in both directions with said closed end of said bellows, theother-arm of said bell crank extending into intersecting relation withthe extended axis of said valve seat, and a needle valve cooperable withsaid seat universally connected to said other arm, the last mentionedconnection being so constructed and arranged as to cause constantlypositive equal movement of said needle valve and said other arm in bothdirections axially of said valve seat, said screw being movable toaposition to move said closed end of said bellows to positively unseatsaid valve.

5. An expansion valve structure including 1 V combination, a housinghaving a valveseat therein, a needle valve member having the point thereof arranged in cooperative relation with said valve seat serving tocontrol the passage of fluid therethrough, a fluid pressure responsivedevice for actuating said needle valve member, a bell crank arm servingto interconnect said fluid, pressure responsive device and said needlevalve member,.. said bell crank arm being pivotally connected to saidfluid pressure responsive device for positive equal movement therewithin'both directions, a universal connection for interconnecting said bellcrank arm and needle valve member serving to permit a limited universalmovement of said needle valve member with respect to its seat and at thesame timeserving to efiect positivee'qual movement of said needle valvemember with said arm'in both directions, means in said universalconnection serving to lock said needle valve member againstr'otationabout its own axis and a fixed pivotal mounting for saicl'bell crank armwithin said housing whereby as said arm is moved said needlevalve.member will be moved' toward or away from its seat in a. directionparallel to its EDWARD R. 15E LUIZ.

